lichess-org/stockfish.js

The strong open source chess engine Stockfish compiled to JavaScript and WebAssembly using Emscripten

stockfish.js

The strong open source chess engine Stockfish compiled to JavaScript and WebAssembly using Emscripten. See it in action for local computer analysis on lichess.org.

Maintained with bugfixes to keep supporting older browsers, but active development is happening on stockfish.wasm.

Releases

About 1.4MB uncompressed, 250 KB gzipped.

Building

Install Emscripten and uglifyjs, then:

./build.sh

Or using Docker:

docker run --user $(id -u):$(id -g) --volume $(pwd):/home/builder/stockfish.js:rw niklasf/emscripten-for-stockfish

Usage

var wasmSupported = typeof WebAssembly === 'object' && WebAssembly.validate(Uint8Array.of(0x0, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00));

var stockfish = new Worker(wasmSupported ? 'stockfish.wasm.js' : 'stockfish.js');

stockfish.addEventListener('message', function (e) {
  console.log(e.data);
});

stockfish.postMessage('uci');

Changes to original Stockfish

• Expose as web worker.
• Web workers are inherently single threaded. Limit to one thread.
• Break down main iterative deepening loop to allow interrupting search.
• Limit total memory to 32 MB.
• Disable Syzygy tablebases.
• Disable benchmark.

Acknowledgements

Thanks to @nmrugg for doing the same thing with Stockfish 6, to @ddugovic for his multi-variant Stockfish fork and to the Stockfish team for ... Stockfish.

stockfish.js's Issues

Error on build with latest version of emscripten

Following instructions from the readme and emscripten, I get this error

stockfish.js git/ddugovic  
❯ ./build.sh


Config:
debug: 'no'
sanitize: 'no'
optimize: 'yes'
arch: 'any'
bits: '32'
kernel: 'Darwin'
os: ''
prefetch: 'no'
popcnt: 'no'
sse: 'no'
pext: 'no'

Flags:
CXX: em++
CXXFLAGS: -Wall -Wcast-qual -std=c++11  -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DNDEBUG -O3 -mdynamic-no-pic -DNO_PREFETCH -flto
LDFLAGS:  -s TOTAL_MEMORY=33554432 --memory-init-file 0 -s NO_EXIT_RUNTIME=1 -s EXPORTED_FUNCTIONS=[_main, _uci_command] -s EXTRA_EXPORTED_RUNTIME_METHODS=[ccall] --pre-js pre.js -s WASM=0 -s LEGACY_VM_SUPPORT=1 -O3 -Wall -Wcast-qual -std=c++11  -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DNDEBUG -O3 -mdynamic-no-pic -DNO_PREFETCH -flto

Testing config sanity. If this fails, try 'make help' ...

/Library/Developer/CommandLineTools/usr/bin/make ARCH=js COMP=emscripten all
em++ -Wall -Wcast-qual -std=c++11  -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DNDEBUG -O3 -mdynamic-no-pic -DNO_PREFETCH -flto   -c -o bitbase.o bitbase.cpp
em++ -Wall -Wcast-qual -std=c++11  -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DNDEBUG -O3 -mdynamic-no-pic -DNO_PREFETCH -flto   -c -o bitboard.o bitboard.cpp
clang-13: error: unsupported option '-mdynamic-no-pic' for target 'wasm32-unknown-emscripten'
clang-13: error: unsupported option '-mdynamic-no-pic' for target 'wasm32-unknown-emscripten'
em++: error: '/Users/robertwebb/emsdk/upstream/bin/clang++ -DEMSCRIPTEN -fignore-exceptions -flto=full -Xclang -iwithsysroot/include/SDL -target wasm32-unknown-emscripten -D__EMSCRIPTEN_major__=2 -D__EMSCRIPTEN_minor__=0 -D__EMSCRIPTEN_tiny__=14 -D_LIBCPP_ABI_VERSION=2 -Dunix -D__unix -D__unix__ -flegacy-pass-manager -Werror=implicit-function-declaration --sysroot=/Users/robertwebb/emsdk/upstream/emscripten/cache/sysroot -Xclang -iwithsysroot/include/compat -Wall -Wcast-qual -std=c++11 -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DNDEBUG -O3 -mdynamic-no-pic -DNO_PREFETCH -flto -c bitboard.cpp -o bitboard.o' failed (1)
make[1]: *** [bitboard.o] Error 1
make[1]: *** Waiting for unfinished jobs....
clang-13: error: unsupported option '-mdynamic-no-pic' for target 'wasm32-unknown-emscripten'
clang-13: error: unsupported option '-mdynamic-no-pic' for target 'wasm32-unknown-emscripten'
em++: error: '/Users/robertwebb/emsdk/upstream/bin/clang++ -DEMSCRIPTEN -fignore-exceptions -flto=full -Xclang -iwithsysroot/include/SDL -target wasm32-unknown-emscripten -D__EMSCRIPTEN_major__=2 -D__EMSCRIPTEN_minor__=0 -D__EMSCRIPTEN_tiny__=14 -D_LIBCPP_ABI_VERSION=2 -Dunix -D__unix -D__unix__ -flegacy-pass-manager -Werror=implicit-function-declaration --sysroot=/Users/robertwebb/emsdk/upstream/emscripten/cache/sysroot -Xclang -iwithsysroot/include/compat -Wall -Wcast-qual -std=c++11 -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DNDEBUG -O3 -mdynamic-no-pic -DNO_PREFETCH -flto -c bitbase.cpp -o bitbase.o' failed (1)
make[1]: *** [bitbase.o] Error 1
make: *** [build] Error 2
                                    

This is probably due to latest emscripten being incompatible with this build, going to try to find either a different stockfish js or the correct version of emscripten to use.

latest merge seems to break search on lichess.org

Web Assembly Engine Can't Find .wasm File

So i'm having an issue in my code where the stockfish.wasm.js file can't find the stockfish.wasm file.

myFunctions.loadChessEngine = function() {
    if(!lozzaObjectURL) {
        lozzaObjectURL = URL.createObjectURL(new Blob([GM_getResourceText('stockFish.js')], {type: 'application/javascript'}));
    }
    if(!wasmObjectURL) {
       wasmObjectURL = URL.createObjectURL(new Blob([GM_getResourceText('stockFish.wasm.js')], {type: 'application/javascript'}));
    }
    if(!wasmFile) {
      wasmFile = URL.createObjectURL(new Blob([GM_getResourceText('stockFish.wasm')], {type: 'application/wasm'}));
    }
    console.log(lozzaObjectURL);
    console.log(wasmObjectURL);
    var wasmSupported = typeof WebAssembly === 'object' && WebAssembly.validate(Uint8Array.of(0x0, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00));
    console.log('Webassembly supported: '+wasmSupported);
    if(lozzaObjectURL && wasmObjectURL) {
        engine.engine = new Worker(wasmSupported ? wasmObjectURL : lozzaObjectURL);
        //engine.engine = new Worker(lozzaObjectURL);

        engine.engine.onmessage = e => {
            parser(e);
        };
        engine.engine.onerror = e => {
            console.log("Worker Error: "+e);
        };

        engine.engine.postMessage('ucinewgame');
    }
    console.log('loaded chess engine');
}

(The code tag wasn't working on GitHub for me. :( )
I'm currently trying to load the files through blob and stockfish.wasm.js can't find the stockfist.wasm file.

Firefox : the local engine doesn't start with n best lines if n-1 possible moves #274

@Vinvin20:

Here, there's only 3 possibles moves: https://fr.lichess.org/analysis/standard/3k4/p2n4/Pp2Q3/4P3/5qPb/1N6/1P5K/6B1_w_-_-_5_44
the local engine doesn't start with 4 best lines

https://fr.lichess.org/IQbOWke5#88
with 1 best line, it's OK
with 2 or 3 best lines, the engine doesn't start

Not recognizing "eval" token

The engine doesn't seem to be responding to eval UCI command, is there a specific UCI sequence needed for debug output?

safari js error with unoptimized build

	optimize=no	optimize=yes
Chrome 57	✔	✔
Firefox 49	✔	✔
Safari 9.1.3	:-(	✔

The js error:

TypeError: Module['___cxa_is_pointer_type'] is not a function.
(In 'Module['___cxa_is_pointer_type'](throwntype)', 'Module['___cxa_is_pointer_type']' is undefined)

Built with OS X 10.11.6, LLVM 8.0.0, emscripten 1.37.1. I was trying to debug the wonky elapsed clock in safari, but it's difficult to trace through without optimize=no.

Error with WebAssembly engine

When I try to use the web assembly version I get an error in the browser

This is how I serve the wasm files with NestJs

@Get('webworker-wasm.js')
private getWebworkerWasmSfjs(req: Request, res: Response) {
    Logger.Info('Serving file ../../node_modules/stockfish.js/stockfish.wasm.js');

    fs.readFile('../../node_modules/stockfish.js/stockfish.wasm.js', 'utf8', (err: any, data: string) => {
        // Buffer.concat(data)
        if (err) {
            console.log(err);
        }

        res.setHeader('Access-Control-Allow-Origin', '*');
        res.setHeader('Access-Control-Request-Method', '*');
        res.setHeader('Access-Control-Allow-Methods', 'OPTIONS, GET');
        res.setHeader('Access-Control-Allow-Headers', '*');
        // res.setHeader('Content-Type', 'application/wasm');
        res.setHeader('Content-Type', 'application/javascript');

        // res.writeHead(200, {'Content-Type': 'application/wasm'});
        res.status(200).end(data);
    });
}

@Get('stockfish.wasm')
private getWebworkerWasmSf(req: Request, res: Response) {
    Logger.Info('Serving file ../../node_modules/stockfish.js/stockfish.wasm');

    fs.readFile('../../node_modules/stockfish.js/stockfish.wasm', 'binary', (err: any, data: Buffer) => {
        // Buffer.concat(data)
        if (err) {
            console.log(err);
        }

        res.setHeader('Access-Control-Allow-Origin', '*');
        res.setHeader('Access-Control-Request-Method', '*');
        res.setHeader('Access-Control-Allow-Methods', 'OPTIONS, GET');
        res.setHeader('Access-Control-Allow-Headers', '*');
        res.setHeader('Content-Type', 'application/wasm');

        // res.writeHead(200, {'Content-Type': 'application/wasm'});
        res.status(200).end(data);
    });
}

In my browser I execute it as follows

 engine = new Worker(`http://localhost:${this.port}/files/webworker-wasm.js`);
 engine.postMessage('uci');
 engine.postMessage('setoption name Move Overhead value 200');
 engine.postMessage('position fen rnbqkbnr/pppppppp/8/8/8/P7/1PPPPPPP/RNBQKBNR b KQkq - 0 1');
engine.postMessage('go  wtime 59000 btime 60000');

Maybe I'm serving the files wrong or am I using wrong options. Any suggestions?

em++:Permission denied while running with docker

cannot run with docker. Getting this permission error inside docker container.

vjuneja$ docker run --volume $PWD:/home/builder/stockfish.js --user $(id -u) niklasf/emscripten-for-stockfish
Makefile:613: recipe for target '.depend' failed
make: [.depend] Error 127 (ignored)

Config:
debug: 'no'
sanitize: 'no'
optimize: 'yes'
arch: 'any'
bits: '32'
kernel: 'Linux'
os: 'GNU/Linux'
prefetch: 'no'
popcnt: 'no'
sse: 'no'
pext: 'no'

Flags:
CXX: em++
CXXFLAGS: -Wall -Wcast-qual -std=c++11  -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DUSELONGESTPV -DNDEBUG -O3 -DNO_PREFETCH
LDFLAGS:  -s TOTAL_MEMORY=33554432 --memory-init-file 0 -s NO_EXIT_RUNTIME=1 -s EXPORTED_FUNCTIONS=[_main, _uci_command] --pre-js pre.js --post-js post.js -O3

Testing config sanity. If this fails, try 'make help' ...

make ARCH=js COMP=emscripten all
make[1]: Entering directory '/home/builder/stockfish.js/src'
Makefile:613: recipe for target '.depend' failed
make[1]: [.depend] Error 127 (ignored)
em++ -Wall -Wcast-qual -std=c++11  -DANTI -DATOMIC -DCRAZYHOUSE -DHORDE -DKOTH -DRACE -DTHREECHECK -DUSELONGESTPV -DNDEBUG -O3 -DNO_PREFETCH   -c -o bitbase.o bitbase.cpp
make[1]: execvp: em++: Permission denied
<builtin>: recipe for target 'bitbase.o' failed
make[1]: *** [bitbase.o] Error 127
make[1]: Leaving directory '/home/builder/stockfish.js/src'
Makefile:491: recipe for target 'build' failed
make: *** [build] Error 2
vjuneja$

Tried running assudo as well.

[Feature request] NPM package

Hello,

Is it possible to get a compiled version with a npm package ?

Thank you.